#gridPanel{
  width:480px; height:480px;
  margin:0 auto;
  background-color:#bbada0;
  border-radius:10px;
  position:relative;
}
.grid,.cell{
  width:100px; height:100px;
  border-radius:6px;
}
.grid{
  background-color:#ccc0b3;
  float:left; margin:16px 0 0 16px;
}
.cell{
  position:absolute;
  font-size:60px;
  text-align:center;
  line-height:100px;
  color:#fff;
}
/*第1行所有格: top:16px*/
[id^="c0"]{top:16px}
/*第2行所有格: top:132px*/
[id^="c1"]{top:132px}
/*第3行所有格: top:248px*/
[id^="c2"]{top:248px}
/*第4行所有格: top:364px*/
[id^="c3"]{top:364px}
[id^="c4"]{top:480px}
[id^="c5"]{top:596px}

/*第1列所有格: left:16px*/
[id$="0"]{left:16px}
/*第2列所有格: left:132px*/
[id$="1"]{left:132px}
/*第3列所有格: left:248px*/
[id$="2"]{left:248px}
/*第4列所有格: left:364px*/
[id$="3"]{left:364px}
[id$="4"]{left:480px}
[id$="5"]{left:596px}

.n2{background-color:#eee3da}
.n4{background-color:#ede0c8}
.n8{background-color:#f2b179}
.n16{background-color:#f59563}
.n32{background-color:#f67c5f}
.n64{background-color:#f65e3b}
.n128{background-color:#edcf72}
.n256{background-color:#edcc61}
.n512{background-color:#9c0}
.n1024{background-color:#33b5e5}
.n2048{background-color:#09c}
.n4096{background-color:#a6c}
.n8192{background-color:#93c}
.n2,.n4{color:#776e65}
.n1024,.n2048,.n4096,.n8192{font-size:40px}

p{
  width:480px; margin:0 auto;
  padding-top:15px;
  font-size:40px; font-weight:bold;
  font-family:Arial;
}

#gameOver{display:none;
  position:absolute; top:0;left:0;
  width:100%; height:100%;
}
#gameOver>div{
  width:100%; height:100%;
  background-color:#555; opacity:0.5;
}
#gameOver>p{
  position:absolute; 
  width:300px; height:200px;
  top:50%; left:50%;
  margin-top:-100px; margin-left:-150px;
  background-color:#fff;
  text-align:center;
  line-height:1.5em;
  border-radius:10px;
  border:1px solid #edcf72;
}
#gameOver .btn{cursor:pointer;
  padding:10px; color:#fff;
  background-color:#9f8d77;
  border-radius:6px;
}